[Prostate cancer of unknown primary origin with multiple lymph nodes metastasis; a case report].

A 62-year-old man were referred our hospital complaining of high prostate specific antigen (PSA) value (32.4 ng/ml) in May 2010. Two sets of biopsies preformed previously at another hospital had not detected any cancers in the prostate. In our hospital, prostate biopsies were performed in July 2010 and February 2011, but cancer was not detected in either occasion. In March 2011, his PSA increased up to 126.7 ng/ml, CT scan showed the swelling of left supraclavicular and para-aortic lymph nodes. Biopsy of the supraclavicular lymph node was performed. Pathology revealed poorly differentiated adenocarcinoma with positive immunohistochemistry for PSA, which was suggestive of metastatic prostate cancer. After 1 year of treatment with androgen deprivation therapy, the patient developed castration resistant prostate cancer and have undergone chemotherapy with docetaxel.